Boring-bar.



UN 171%@ STATE@ ld @Fhll JACOB VAN DER VORN, OF MILWAUKEE, WISCONSN, ASSGNOR TO EXEANDEM dTOOL AND IVIATUFACTURING COMPANY,

A CORPBATION OF LLNOIS, l

noniaie-nan` Specification. of Letters Patent.

Patented July 3, 1991*?.

To all whom t may concern.

Be it known that LJACB VAN Dnu Venu, a citizen of the United States, and uesident of Milwaukee, in the countyy of lrlilwaukee and State of Wisconsiinhaih invented new and usefulimprovements in Boring-Bars, of which the following is a description, rei!- erence being had to the iiccoinpanying drawings-'which are a part of this specification^ The invention relates to boring bars.

The invention is designed more particularly to provide means whereby the boring tools or cutters may be held in the boring bar and adfusted 'for use as required.

In devices of this character', simplicity, accuracy, ease of operation and fewness of parts are prime requisites and the present invention has been. designed to satisfy these requisites only three working parte 'besides the tools being used thus'rcducing the chance in inaccuracies of construction Ywhich would necessarily result as the number of parts is increased and also reducing the cost of manufacture and producing a device sirnple in operation The invention further consists in the several features hereinafter set forth and more particularly defined loy claims at the corr clusion hereof.

ln the drawings:

Figure 1 is an elevation view of thev devicc embodying the invention;

Fig. 2 is a section taken on the line of Fig. 1 g

Figfy is a section. taken on the line 3-3 of Fig. 2;

Fig. el is a section token on the line F4 of Fig. 1.

In the drawings the nunieral 5 designates the working' end portion of the cylindrical boring bar which has a diametrically ei;- tending cylindrical'hore or aperture (5, a longitudinallyv extending slot 7 communicating at its upper end with the aperture G and in line therewith but of less width than the diameter oi the aperture (i, a cylindrical aperture 8 at right angies to the aperture and leading from one side into said aperture, a threaded bore il at right angles to the slot 7 and, communicating with thelower end thereof und having a smaller hearing aperture 10 communicating with its bottom and coaxial with said aperture 9.

Disposed within the bore 6 is a right and lett' hand threaded tool-feeding and adjusting screw 12 having a reduced central portion 13 forming a groove to receive a projection 14 extending 'from a plug or block 15 tightly fitted into the aperture 8 wherehy the screw 12 is free to rotate in the bore (i but is prevented from moving laterally. The screw 12 is provided with a square recess 12 for receivingthe end of a key to turn it.

Disposed within the lower portion of the slot 7 is a clamping block 16 having a finished ltool engaging surface 17 and a slightly'tapered centrally disposed notch 1S. interposed between the screw 12 and the block 1G are the tools 19 having` accurately finished threads or worm racks 20 adapted 'o directly and rcsl'iectively engage with the right and left hand screw member and having finished plain surfaces 20 adapted to engage the surface 17 of the block 16. v

The block 16 is held in clamping engagenient with the tools and the tools thereby ciainped between the screw 12 and said hlock hy means cit a screw 21 having a threaded portion Q2 in threaded engagement with here 9, a tapered portieri 2S in engagement with the notch 1;? in the block 16 and a straight cylindrical portion 24 having its hearing in the aperture 10, said screw Q1 also having a square recess 25 therein ior receiving a key to turn the screw into the bur and tlierehy wedge the tapered portion 23 against the bloei; 16 thus moving said block against the tools which are consequently tightly held against the adjusting screw 12 and thus locked in position.

7frih iluconstruction above described to adjust the tools il. is only necessary to insert the hey and loosen the screw 21 slightly and then hy inserting the, key in tlu` recess 12' and turning thel screw 1Q in the desired direction the toolsll may he moved inwardly or outwardly :is desired and be locked in plm-,e by screwing in tile screw Q1 against the block 16u ln devices of this character the boring bar usually carries several tools to make the roughening and the iinished cuts and it will he noted that the construction heretofore. described is such as to he used at any place along the har and that the clamping means is located in bach' o1 the clamping block.

lt will he noted that the adjusting screw times and that by making` an accurate fit between these parts the chance for error is much less 'than which use a block or blocks interposed between the adjusting screw and the tools and also that the entire portion of the tool held within the bar has its bearing upon the ad- Justing screw and the clamping block thus assuring a tight fit between the parts to resist strain.

It will be noted that due to the arrangement and fewness of parts that the operation is simple, the device linexpensive and capable of accurate work.

IVhat I claim as my invention is:

l. In a boring tool, the combination of a bar, a right and left hand threaded adjusting screw mounted within the bar, a cla1nping block within the bar, a pair of cutting tools carried hy the har, each having a threaded edge in direct engagement with the screw and their other opposite edge in direct engagement with the block, and means for clamping the tools between the screw and the block. y

2. In a boring tool, the combination of in those devices of this type a har, a right and left hand threaded adjusting screw mounted within the bar, a clamping block within the bar, cutting tools carried by the bar, each having a threaded edge in direct engagement with the screw and their opposite edge in direct' engagement with the block, and a locking screw wedgingly engaging the block to clamp the tools between the adjusting screw and said.

block.

3'. In aboring tool, the combination of a bar, a right and left hand threaded adjusting screw mounted within the bar, a clamping block mounted within the bar and provided with a notch, a pair of ,cutting tools disposed between and in direct engagement with said screw and clamping block and provided be moved on the rotation of said screw, and a locking screw withinv the barA having a tapered portion engaging in the notch of said clamping block to clampI the tools be`J tween the adjusting screw and said block. In testimonyT whereof Iaix my signature,

JAooB VAN4 DER, voRn.

with threads so as to', 

